Yes it is, Muslims and Mormons, and Episcopalians all have religious views on what marriage is.
The Mormon Pope could have a new revelation returning polygamy , at any moment.
>> Mormon Pope
Bigot.
That's why I think this should be looked at as an important tax issue. Limit "head of household" to no more than two adults. If Mormons want to return to polygamy, let them do it sacramentally. Any adult dependents in the household should be limited to only those with physical/mental incapacitations (aged parents, adult children with severe disabilities).